Such boost pressure control is known from DE 195 02 150 C1, for example. In this case a boost pressure control device includes an integral action controller whose integration of the control deviation is limited to a predetermined limit value to avoid severe overshooting. For this purpose various limit values are specified for stationary and for dynamic operating states, whereby the dynamic limit value is provided with corrections that are dependent on the operating characteristics and is provided with an adaptive correction, and in addition is increased by a safety margin. The aim is to ensure consistently good quality of control, even when the components involved in the control are subject to contamination or wear. Similar boost pressure control is also known from DE 198 12 843 A1, in which, for operation of the boost pressure control over a broad operating range without excessively retarding the control process or causing overshooting in the control, a manipulated variable for an actuator is transformed to values such that after transformation of the values, a linear relationship exists between the manipulated variable and the control variable. A correction value for a limit value which is specified for an integral portion of an integral action controller is also known in conjunction with boost pressure control from DE 197 12 861 A1.
Due to serial dispersion dictated by the manufacturing process, for example in spring pretensioning in the waste gate region, such as in the specific region of a spring-loaded pressure box which acts on a bypass valve, for some vehicles a different control characteristic is obtained which is undesirable. The same also applies to aging symptoms of the components of a controlled system, which likewise may vary from vehicle to vehicle.
The object of the present invention, therefore, is to provide a method and a device for controlling boost pressure in an internal combustion engine by means of which, in particular for serial dispersion and aging symptoms of the components of the controlled system, a high-quality and reproducible control may be provided with the lowest possible control deviation between the setpoint boost pressure and the actual boost pressure.